In recent years, digital technology has trickled into every aspect of our analog life. Most recently, there is a surge in digital technology to replace or enhance our visual experiences. Head-mounted displays (HMDs) have been around for years; however, as computers get more powerful, the visual effects provided by the computers are getting more spectacular, resulting in a resurgence of HMDs.
An HMD is a display device worn on the head of a user or as part of a helmet worn by the user. The HMD may incorporate an opaque display optic positioned in front of one eye (monocular HMD) or each eye (binocular HMD) of the user. Alternatively, an optical HMD is a wearable device, also worn on the head of user that incorporates transparent optics that have the capability of relaying projected images to the viewer while allowing the viewer to see the exterior, real-world environment. One example of a HMD includes a small display optic (e.g., data glasses or a visor) in front of one or both eyes. The HMD may be an optical head-mounted display (OHMD) configured to reflect projecting images on an optical element (e.g., a visor or lens) and allow the user to see through the optical element. HMDs may have one or two small optical elements with lenses and semi-transparent mirrors embedded within data glasses or a visor. The display may be a cathode ray tube (CRT), a liquid crystal display (LCD), liquid crystal on silicon (LCoS), or organic light-emitting diode (OLED). In some implementations, the display may be a laser-based light source. A laser-based light source may comprise one or more of a laser, an RGB laser, and/or other laser-based light sources. In some implementations, a laser-based light source may be coupled with one or more directional control devices, such as a micro-electrical-mechanical system (MEMS), a beam steering device, and/or other devices. In some examples, the display includes multiple micro-displays to increase the total resolution and field-of-view, therefore providing a better experience to the user. HMDs are used in many applications including military, governmental, and civilian/commercial (e.g., movies, video gaming, sports, etc.), among others.
HMDs may be used to replace our visual experience (e.g., via Virtual Reality (VR)) or enhance our visual experience (e.g., via Augmented Reality (AR)). VR, sometimes referred to as immersive multimedia or computer-simulated reality, replicates an environment that simulates a physical presence in places in the real world or an imagined world. VR allows the user to interact with that world. Moreover, VR may artificially create sensory experiences relating to the virtually created world, which may include one or more of sight, touch, audio, and/or smell. AR is a live direct or indirect view of a physical, real-world environment that includes augmented or supplemented elements generated by a computer having sensory inputs. The sensory inputs may include one or more of a sound, a video, graphics, and/or position data. AR modifies the view of reality by using a user device, coupled with an application executing on the user device. Furthermore, AR functions by enhancing, altering, or modifying a user's perception of reality, which may be different from virtual reality that replaces the real world with a simulated one. AR applications may provide the user with a real-time experience in relation and in context with environmental elements around the user. AR applications allow a user to interact with his/her environment and objects within the environment and manipulate the AR associated with the environment.